Hello i am new to asp/javascript word..
I have a web form where i have declared a checkboxlist without any listitems as i dont know in compile time how many i want.In runtime i want to add/append items to my checkboxlist but in client side that means work with javascript.

When i am trying to access my checkboxlist through js i get message error
null/undefined object( "object is null or undefined" )

The checkboxlist is declared in my aspx as:
<asp:CheckBoxList id="cbxlst_Addr" runat = "server">
</asp:CheckBoxList>
So, whats wrong?